The present invention relates to an improved liner for rehabilitating pipes, passages, and manholes. In particular, the present invention relates to a multiply internal lining for an eroded or damaged pipe, manhole, or passageway, in which a felt impregnated vinyl ply is mechanically locked to inner and outer resin hardened fiberglass plies.
Waste water is transported through a system of conduits, known as sewers, from the point of generation to a remote treatment or disposal site. Frequently, the exposed surfaces become deteriorated, resulting in undesirable leakage and difficulty with the flow of the fluid. The sewers are typically provided with a vertically disposed manhole. The manhole has an opening at the surface or grade level. The lower or invert end of the manhole has a flow path, known as a lateral, through which sewage flows on its way to the treatment plant. The manhole may be formed of cement, concrete or brick, and typically has an internal diameter many times greater than the diameter of the flow path of the lateral.
The sewage may generate an atmosphere which is damaging to the mortar with which a brick manhole is formed. Alternatively, the environment may be damaging to the cementitous material used in manufacturing the manhole. Should the manhole be damaged, then rainfall or surface water may enter the manhole, thereby overloading the sewage system and potentially causing untreated sewage to be discharged into streams, lakes, and the like. Preserving the structural integrity of manholes is one means of minimizing the load applied to a sewage pumping treatment plant. These problems also apply to sewage stations, which are located along the sewage collection system, and which may also require rehabilitation.
In the past, systems have been developed to rehabilitate or repair damaged manholes. For instance, my prior U.S. Pat. No. 5,265,981, the disclosure of which is incorporated herein by reference, discloses a system and method for rehabilitating a manhole. In that system, inner and outer fiberglass plies sandwich a middle impermeable ply. The outer ply is adapted for being impregnated with a material which rigidities the outer ply to the manhole. The middle ply is impermeable and prevents fluid from seeping into the manhole. The inner layer is also impregnated with a material which rigidifies the inner layer, so that the manhole becomes structurally reinforced. My prior U.S. Pat. No. 5,490,744, the disclosure of which is incorporated herein by reference, discloses a method and apparatus for inflating and curing a resin impregnated manhole liner.
My above described patents constituted a significant and advantageous improvement in the art. However, further improvement is virtually always possible in any field of endeavor, which turned out to be true here. For example, because the middle ply is made from an impermeable material, it is slick and may not always bond well to the epoxy impregnated inner and outer plies. Thus, while the manhole is structurally reinforced, there still remains a risk of the inner reinforced layer prying loose.
Thus, there is a need in the art for a liner for sealing and reinforcing a manhole, in which an impermeable middle layer is structurally bonded with the inner and outer plies, providing extra structural reinforcement.
A principal object of the present invention is to provide a liner for sealing and reinforcing a manhole which provides extra structural reinforcement to the manhole.
The above object is achieved according to the present invention.
A liner assembly for sealing and reinforcing a manhole is provided. The assembly includes a multiple ply contoured tube having first, second, and third oriented plies. The first ply includes inner and outer surfaces for being impregnated with a material for rigidifying and binding the outer surface of the first ply to the interior of the manhole. The third ply includes inner and outer surfaces for being impregnated with a material for rigidifying the inner surface of the third ply, so that the interior of the manhole is structurally reinforced. The second ply is impermeable to fluids, and is disposed between the first and third outermost plies. The second ply includes an impermeable membrane having fibers impregnated on inner and outer surfaces of the second ply, but not penetrating the membrane. The outer surface of the second ply is bonded to the inner surface of the first ply, and the inner surface of the second ply is bonded to the outer surface for the third ply. The liner assembly includes means for securing the outermost, innermost, and impermeable plies together, so that the plies are facially oriented.
A rehabilitated manhole is provided. The manhole includes a vertically disposed manhole having an upper end, internal walls, and a lower end with at least one lateral. A reinforcing system is positioned within the manhole. The reinforcing system includes a support tube assembly comprising first, second, and third juxtaposed layers, with the first and third layers formed from a woven, structural material. The second layer is disposed between the first and third layers, and is formed from a membrane impermeable to fluids and has fibers impregnated on its first and second surfaces, but not penetrating through the membrane. Each of the first and third layers is impregnated with an epoxy resin system, so that the first and third layers are rigidified and the third layer is bonded to the internal walls and lower end of the manhole. In addition, the fibers on the first surface of the second layer are bonded to the inner surface of the third layer, and the fibers on the second surface of the second layer are bonded to the outer surface of the first layer. Each of the layers is cut proximate to the lateral for permitting access thereto.
These and other objects and advantages of the invention will be readily apparent in view of the following description and drawings of the above described invention.